From United States Patent Application Publication US 2006/0080495, a data communication system is known. The data communication system has a central control unit, decentralized data processing units and a data connection between the central control unit and the decentralized data processing units. During the transmission, in order to request data packets, the central control unit periodically outputs synchronization pulses over the data connection to the data processing unit interface, whereupon the decentralized data processing unit transmits data packets to the central control unit. The decentralized data processing unit generates an electrical discharge pulse after the synchronization pulse but before the transmission of a first data packet, thereby counteracting an electrical charging of the data processing unit interface by the synchronization pulse.
However, a disadvantage of the data communication system described in this Patent Application Publication, is that it consumes a significant amount of power. In particular the synchronisation pulse as well as the discharge pulse consume a significant amount of power. Furthermore, a separate power supply is required to generate the synchronisation pulse.